The hypocentre is the “focus” point within the ground where the strain energy of the earthquake stored in the rock is first released.

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What are the three types of seismic waves?

The three types of seismic waves are primary waves, secondary waves and love waves.

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What are primary waves?

Primary waves are vibrations caused by compression which spread quickly from the fault at around 8km/sec.

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What are secondary waves?

Secondary waves are waves that more more slowly at around 4km/sec which vibrate at right angles to the direction of travel and CANNOT travel through liquids.

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What are love waves?

Love waves (also known as Q waves) are surface waves with the vibration occurring in the horizontal plain. They have a high amplitude.

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What is one of the most serious second hazards of an earthquake?

One of the most serious second hazards of an earthquake is soil liquefaction.

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What does soil liquefaction do?

Soil liquefaction causes buildings to settle, tilt and then collapse. In some earthquakes tilts of up to 60 degrees have been recorded, for example Japan.

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What is soil liquefaction?

Soil liquefaction is actually the process by which water-saturated material can temporarily lose normal strength and behave like a liquid under pressure of strong shaking.

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What is the epicentre?

The epicentre is the location on the Earth’s surface that is DIRECTLY ABOVE the earthquake focus, i.e the point where an earthquake originates.

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What is another important secondary factor regarding earthquakes?

Another important secondary factor regarding earthquakes is landslides.

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Why are landslides so dangerous?

Landslides are so dangerous because they form on highly susceptible slopes and research from the USGS suggests that over the last 40 years 70% of all deaths caused by earthquakes globally are attributable to (secondary) landslides.

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Landslide statistics to prove how dangerous they are?

Landslide statistics include - 2005, Kashmir and 2008, Sichuan, in both cases landslides caused A THIRD OF ALL DEATHS.